Gas lift valve



pr 2,1968 c. R. CANALIZO 3,375,846

GAS LIFT VALVE Filed Nov. 22, 1963 FIG. 3

INVENTOR. CARLOS R. CANALIZO BYMWLW FIG. 2 fi-M United States Patent3,375,846 GAS LIFT VALVE Carlos R. Canalizo, Dallas, Tex., assignor toOtis Engineering Corporation, Dallas, Tex., a corporation of DelawareContinuation-impart of application Ser. No. 277,064, Apr. 9, 1963. Thisapplication Nov. 22, 1963, Ser. No. 325,716

17 Claims. (Cl. 137-155) This invention relates to well tools and moreparticularly to well tools for removing fluids from the bores of wellsby gas pressure, such as air or gas lift valves.

This application is a continuation-in-part of my copending application,Ser. No. 277,064, filed Apr. 9, 1963, now abandoned, which latterapplication was a division of my co-pending application, Ser. No.38,342, filed June 23, 1960, now Patent No. 3,130,793.

An object of the invention is to provide a new and improved well toolfor removing the liquids produced by wells through an inner well tubingdisposed in a casing of the well wherein gas from the annular flowpassage between the well casing and the inner well tubing provides thepower for transporting the liquids to the surface through the inner welltubing.

Another object is to provide a well tool for automatically removingliquid from the bore of a well which includes a valve which opensintermittently to permit flow of the gas from the annular flow passagebetween the Well casing and an inner well tubing into the well tubing totransport liquids present in the well tubing above the valve to thesurface.

Still another object is to provide a well tool for use in wells having acasing and an inner well tubing telescoped therein which includes avalve providing communication between. the interior of the well tubingand the annular space between the casing and the well tubing and whichis responsive only to the pressure within the tubing above the valve topermit flow of fluid from the annular space into the tubing when thepressure within the tubing exceeds a predetermined value.

A further object is to provide a well tool for use in wells having acasing and an inner tubing telescoped therein which includes a valveaffording communication between the interior of the tubing and theannular space between the casing and the inner tubing which opens topermit flow of fluid from the well casing into the inner tubing when thepressure within the tubing rises above a predetermined value withoutregard to the value of the pressure in the annular space between thewell casing and the inner tubing and which closes when the pressurewithin the tubing decreases to substantially the same predeterminedvalue at which the valve opens.

Still another object is to provide a new and improved gas lift valve forautomatically removing liquid from the bore of a well which opensintermittently to permit flow of gas introduced into the annular flowpassage between the well casing and an inner well tubing into the welltubing to transport liquids present in the well tubing above the valveto the surface. It is a further particular object of the invention toprovide an improved gas lift valve which will open to admit gas into thetubing from the well bore or the annular space between the well casingand the tubing in a continuous regulated flow to aerate the column offluid in the tubing and lift the same from the well, and wherein thevalve is not affected by the casing pressure but opens in response topredetermined flow conditions within. the tubing string to provide acontinuous regulated flow of lifting gas at high efficiency therebyusing a minimum volume of gas to effect continuous flow from the well.

Still another object of the invention is to provide a gas lift valve ofthe character described for metering the flow of gas into the tubingwhich is provided with resilient means for controlling actuation of thevalve and means for preventing application of excessive fluid pressureto such resilient means.

Still another object of the invention is to provide a gas lift valvewhich is unaffected by casing pressure and is thus suitable for use inmultiple string gas lift installations, wherein each string of themultiple strings of tubing conducts production from a separate formationto the surface and has present therein a flow condition differing fromthe flow conditions in the other strings of tubing; such gas lift valvebeing unaffected by easing pressure so long as the casing pressure issufliciently high to exceed the fluid pressure within the tubing string,whereby said valve controls the injection of lifting fluid from thecasing annulus into each of the several tubing strings to flow thefluids present in such tubing string to the: well, the gas lift valvebeing subject to control of its operations only by the fluid pressureconditions present in the tubing string in which the valve is installed.

Additional objects and advantages of the invention will be readilyapparent from the reading of the following description of a deviceconstructed in accordance with the invention, and reference to theaccompanying drawings thereof, wherein:

FIGURE 1 is a vertical sectional view of a portion of a well flowconductor or tubing string having a well tool embodying the inventiondisposed therein for removing fluids from the well;

FIGURE 2 is an enlarged view, partly in elevation and partly in section,of the valve of FIGURE 1, showing the valve in closed position; and,

FIGURE 3 is a view similar to FIGURE 2 of the lower portion of the valveand showing the valve in open position.

Referring now particularly to FIGURES 1 through 3 of the drawings, afluid operated gas lift valve 10 is shown to be removably installed in ahousing or landing nipple 11 connected in a tubing string 12. Thelanding nipple shown is of the type generally referred to as the offsettype, and includes a landing section or pocket 13 which is welded intoan opening in the wall of a housing 14 by means of the welds 15 and islaterally offset from the axis of the housing whereby a flow passage isprovided through the housing past said pocket of a size approximatingthe size of the bore of the tubing string. An eccentric fitting 16 iswelded to the lower end of the housing and is connectable to the tubingsection 12 below the housing, the eccentric bore of the fitting beingaligned with the passage through the housing past the pocket. A similareccentric fitting (not shown) is provided at the upper end of thehousing and in alignment with the fitting 16 and the tubing stringthereabove is connected thereto where-by a continuous, unobstructed anduninterrupted passage is provided through the tubing and the housing.

The landing section or pocket 13 has a. longitudinal bore 17 opening tothe upper end of said landing nipple, and an internal annular lockinggrOOVe or recess 18 is formed in the upper end of the bore wall of thepocket for receiving the locking dog of the well device secured in saidpocket, as will be more fully described hereinafter.

A plurality of ports 21 through the exterior wall of the landing nippleat a point spaced below the locking recess but above the lower end ofthe landing section provide a fluid passage between the exterior of thelanding nipple and the interior of the pocket, and a discharge port 22at the lower end of the pocket permits fluid flow therethrough betweenthe interior of the lower end of the pocket and the interior of thelanding nipple and the tubing string.

The gas lift valve is provided with a locking mandrel 23 which isthreaded onto a screw threaded pin at the upper end of an adapter plug24 which is threaded into and closes the upper end of an elongatetubular chamber member or tube 25 of the gas lift valve. The lockingmandrel 23 includes an expansible and retractable latch means 26 of thecharacter to engage in the locking recess of the pocket. An externalannular flange 27 near the upper end of the locking mandrel isengageable with the upper end of the pocket to limit downward movementof the valve in the pocket and a fishing neck or gripping head 28 at theupper end of the locking mandrel is engageable by a suitable running orretrieving tool (not shown) for inserting the valve into or removing itfrom the pocket.

A packing sleeve 29 having a bore 29a therethrough is threaded into thelower end of the chamber 25 and the lower end of the bore 29a isenlarged and receives the threaded upper end of an elongate tubularvalve body 30 having a bore 31 therethrough. A lateral inlet port 32. isprovided in the wall of the body and a restricted inlet orifice insert33 is threaded into an enlarged portion of the lateral bore in the bodyfor controlling the entry of fluids into the bore of the body as will behereinafter more fully described. A lower tubular sub or packing mandrel34 is threaded into the lower end of the body, and a guide and flow cap35 provided with a plurality of longitudinal flow ports 36 therethroughis threaded onto the lower end of the sub. The lower end of the cap isdownwardly and inwardly beveled or tapered to provide a guide nosewhereby the valve may readily be inserted into the pocket.

An upper packing section 37 shown to be made up of a plurality ofsealing rings of the V-type, is disposed on the outer surface of thebody of the packing mandrel 29 and is retained thereon between anupwardly facing annular shoulder 38 on the body and the lower end of thechamber 25. A lower packing section 39 also shown to be made up of aplurality of sealing rings of the V- type, is disposed on the lowerportion of the lower sub or packing mandrel 34 and is retained thereonbetween a downwardly facing shoulder 40 on said sub and the up- .per endof the flow cap 35. The packing sections 37 and 39 seal between thevalve 10 and the bore wall of the landing nipple or pocket for directingfluid flow from the ports 21 of the landing section or pocket to thelateral flow port 32 of the gas lift valve.

A check valve 41 is disposed in the bore of the lower packing mandrel orlower sub 34 and includes a supporting thimble 42 having a plurality ofradial longitudinally extending narrow slots 43 provided in its outerperiphery to permit flow of fluids through the bore of the lower sub orpacking mandrel to the outlet openings in the cap. The thimble engagesdownwardly facing shoulder 44 in the bore of the lower sub and aresilient elastomeric, rubber or synthetic rubber or the like, cup 45 isconfined between the concave lower surface 46 of the thimble and anupstanding retaining pin or mandrel 47 carried by the cap and engagingthe central recess or counterbore 45a in the downwardly facingcylindrical portion of the resilient cup. The lower end of the pin ormandrel is disposed in an axial counterbore 48 in the cap 35 and thispin may be threaded or have a press fit in said opening if desired tomaintain the same in place in the cap. When the cap is screwed onto thelower end of the lower end of the lower sub, the pin or mandrel pressesthe central portion of the cup 45 firmly into the central portion of theconcave underside of the thimble 42, whereby the cup is firmly held inplace in the thimble and in position to engage the cylindrical bore wallof the enlarged lower portion 49 of the bore of the lower sub or mandrel34. If desired, the external diameter of the resilient cup 45 may beslightly less than the diameter of the enlarged portion 49 of the boreof th lower sub whereby fluid pressure may pass in either direction pastthe resilient cup, but a slight volume of flow in a direction from thecap toward the bore of the sub or mandrel thereabove will immediatelyflex the lip 50 of the cup outwardly into sealing engagement with thebore wall of the lower mandrel or sub. In this manner, back-flow offluids through the mandrel is prevented, but there may be fluid pressurecommunication between the longitudinal ports of the cap and the bore ofthe mandrel or sub above the check valve.

The lower sub of the valve has at the upper end of its bore an upwardlyfacing annular seat ring 48 which is preferably formed of tungstencarbide or other suitable 1 hard material welded, soldered or otherwisesuitably secured in place in an enlarged annular recess 49 formed in theupper end of the sub. A valve head 50 is mounted in the valve housing orbody 30 for limited longitudinal movement between the closed positionillustrated in FIG- URE 2, wherein the hardened tip insert 51 on thelower end of the valve head member 50 engages the hardened seat ringinsert 48 disposed in the upper end of the bore of the lower sub 34, andan upper open position wherein an facing stop shoulder 55 provided by anenlarged external annular flange 56 on an elongate stem or plunger 57connected by screw threads at its lower end to the valve head 50 engagesa downwardly facing internal annular shoulder 58 formed in the bore ofthe upper packing sleeve 49. The valve head 50 and the hardened tip 51thereon are provided with an axial bore 52 which extends upwardlytherethrough and communicates with a counterbore 53 formed in the lowerportion of the stem or plunger 57. A lateral port 54 communicates thecounterbore with the exterior of the reduced lower portion 59 of theplunger below the flange 56 and the bore of the packing mandrel 29,whereby fluid pressure from below the valve head 51 may pass upwardlythrough the bores 52 and 53 and the port 54 to the bore of the packingsleeve or mandrel 29.

When the tip 51 of the valve head is in engagement with the seat 48, itwill be apparent that fluid from the inlet ports 21 of the pocket 13will flow inwardly into the bore 17 of the pocket and be confinedbetween the packing assemblies 37 and 39 and thus directed through theinlet orifice member 33 into the bore of the valve body 30 where it willbe confined between the seat 48 and an internal annular seal ring 60which is disposed in an internal annular groove in the body and engagesthe reduced lower external cylindrical portion 59 of the plunger 57below the port 54. The bore of the valve body also has internal annularrecesses above and below the seal means 66 and in these recesses aredisposed felt wipers 62 which wipe or clean the external surface of thereduced portion 59 of the valve plunger as the valve moves between itsopen and closed positions to prevent access of dirt or foreign matter tothe seal means whereby the life of the seal means is prolonged.

An elongate cylindrical corrugated bellows 65 has a cylindrical annularflange 66 at its lower end secured by welding, soldering or otherwise tothe plunger 57 at a point spaced above the flange 56, and the upperportion of the plunger 57 is reduced in diameter as at 67 whereby thebellows 65 is disposed in the annular space between the packing sleeveor mandrel 29 and the reduced portion 67 of the plunger. The upper endof the bellows has an external annular flange 68 which is welded orsoldered or otherwise suitably secured to the upper end of the packingmandrel 29. The bellows thus provides a gastight fluid seal between theplunger 57 and the packing mandrel and is disposed about the reducedportion 67 of the plunger and spaced inwardly of the internalcylindrical surface of the mandrel, so that the bore of the mandrelopens downwardly and outwardly of the bellows to communicate with theannular space between the enlarged lower portion of the bore 61 of thepacking mandrel and the reduced lower portion 59 of the plunger and thuscommunicates likewise with the lateral port 54 and the flow passage 52through the valve 50 and the valve head 51.

An O-ring 69 is disposed in an external annular groove in the mandrelbetween the mandrel and the lower end of the bore of the tube of thevalve above the packing assembly 37. Similarly, a lower seal ring 70 isdisposed in an external annular groove in the valve body and sealsbetween the valve body and the lower end of the bore of the packingmandrel. An O-ring 71 is disposed in an external annular groove in thelower sub or packing mandrel 34 and seals between the sub and theinternal cylindrical surface of the lower end of the bore of the valvebody. Thus, the various sections of the gas lift valve are suitablysealed against the passage of fluids therebetween from the exterior tothe interior thereof.

The external annular flange 56 of the plunger 57 is provided with anexternal annular recess below the seat or shoulder 55 thereon and anO-ring or other suitable seal ring 64 is disposed in the groove and isadapted to engage such seal against the internal annular seal surface 63in the bore of the mandrel 29 below the stop shoulder 58 when the valveis in its upper open position, whereby the bellows thereabove isprotected from any excessive pressures from interiorly of the tubingpassing upwardly through the valve passage 52 and the counterbore 53 andport 54 in the plunger 57. Also, when the valve head 50 is moved to theopen position shown in FIGURE 3, gas pressure from exteriorly of thetubing entering through the ports 21 and the restricted orifice member33 will be prevented from passing upwardly through the passage 52 of thevalve and the counterbore 53, and port 54 in the plunger to act on thebellows to tend to rupture the same. It will be seen that the engagementof the upwardly facing shoulder 55 on the plunger with the downwardlyfacing shoulder 58 in the mandrel likewise prevents excessive movementof the plunger and thereby also limits the compressive force applied tothe bellows 65 to prevent rupture thereof due to compressive movement,while the seal member 62 prevents excessive fluid pressure from actingon the bellows to tend to rupture the same or otherwise deform or damageit.

When the valve is in the closed position shown in FIG- URE 2, thepressure within the bore of the lower mandrel or sub 34 may passupwardly through the passage 52 in the valve head and the counterbore 53and port 54 in the plunger and act on the bellows to exert a fluidpressure force thereon which tends to move the plunger and the valvehead carried thereby upwardly from the closed position shown in FIGURE 2toward the open position shown in FIGURE 3 wherein the valve tip 51 doesnot engage the seat 48. When the valve is moved to the open position, itis obvious that lifting fluid or gas entering through the orifice member33 may pass downwardly between the valve tip 51 and the seat 48 andthrough the bore of the lower sub and the slots 43 in the thirnble 42past the sealing cup 45 and outwardly through the openings 36 in the capto aerate and lift oil or other fluids present in the bore of the tubingstring.

The valve stem or plunger, 57 is provided at its upper end with anannular ring guide 80 telescoped on the re duced upper end tip portion81 of the plunger or stem. The ring guide is somewhat smaller indiameter than the internal diameter of the bore of the upper portion ofthe tube 25 so that it permits free longitudinal movement of the valveplunger or stem but tends to prevent any substantial lateral movementthereof, when such lateral movements exceed predetermined limits, byengaging the internal surface of the tube 25. The valve stem or plunger57 is biased downwardly toward the lower closed position by a helicalcoil spring 83 which is disposed within the tube 25 and has its lowerend bearing against or supported on the ring guide 80 and its upper endengaging or bearing against an upper adjusting screw 84 threaded intothe internally threaded upper end 87 of the tube 25. The adjusting screw84 is locked against movement from any adjusted position in the tube bymeans of a suitable detent means thereon which may comprise a nylon ballor pellet 85 which is disposed in an external recess or opening in thescrew and frictionally engages the internal threads 87 of the housing toprevent undesired rotation of the screw in the housing. The adjustingscrew is provided at its upper end with a transverse slot or aperture 86by means of which it may be adjusted in position in the threaded bore 87in the upper end of the housing or tube. A longitudinal axial bore 88 isformed in the adjusting screw and provides for equilization of fluidpressures above and below the adjusting screw within the bore of thetube during the longitudinal movement of the valve, since the bellows65, the plunger 66 and the tube 25 together with the adapter plug 24form a closed chamber 89 having no vent. This chamber, if desired, maybe charged with compressible gas to any desired pressure, either greateror less than atmospheric pressure. If desired, a fitting 90 may beprovided in the wall of the tube 25 through which gas may be introducedinto the chamber 89 as desired.

When the pressure in the bore of the housing and in the bore of thetubing string acting upwardly through the inlet opening 22 in the pocketand the passages 36 in the cap 35 past the check valve cup 45 rises tosuch a value that its force on the effective area of the bellows 65overcomes the force of the spring 83 and the pressure of the gasconfined in the closed chamber 89, the valve head 50 is moved toward itsopen position. As soon as the valve tip 51 moves away from the seat 48,the fluid pressure acting through the orifice member 33, which isgreater than the pressure in the bore of the mandrel or sub below theseat 48, enters the flow passage 52 of the valve head and passesupwardly therethrough and outwardly through the lateral port 54 and actsagainst the full eflective area of the bellows 65 to force the valveplunger or stem 67upwardly moving the valve head to its open position,further compressing the spring 83. As the valve moves to its openposition, the O-ring or seal member 64 engages the internal seal surface63 of the packing mandrel 29 and thus protects the bellows against theaction of the full pressure thereon and against collapse due toexcessive pressure by sealing the annular chamber 61. between theplunger 57 and the seal surface below the shoulder 58. The valve isstopped against further upward movement when the external annularshoulder 55 of the plunger engages the downwardly facing stop shoulder58 in the packing mandrel. With the valve thus open, fluids may flowthrough the orifice member 33 into the body and down wardly through thelower sub and past the check valve 45 into the well tubing.

As the well fluids rise in the tubing past the gas lift valve, gascontinuously flows through the gas lift valve to form bubbles in theflowing column, the pressure of the gas assuming the same pressure asthat of the. following column at that point. The pressure will va yslightly, so that as the pressure decreases, the valve tip will movedownwardly relative to the seat 48 and meter the admission of gas intothe well fluids in the tubing to thus reduce the amount of gas beinginjected into the column. If the pressure of the fluid column in thetubing increases slightly the valve head will open slightly to letadditional gas into the tubing, and the valve tip 51 will move upwardlyaway from the seat to increase the annular orifice therebetween andadmit additional gas into the tubing to further aerate the column.

Due to the elongate tapered external surface 51a of the tip 51 of thevalve head being always disposed in the bore of the seat 48, the orificetherebetween will always be a small annular orifice and there will be ametering of the gaseous fluid admitted into the well tubing.

The bore diameter of the intake port or orifice 33 is large as comparedto the annular orifice provided by the valve head 50 and the seat 48 sothat the orifice 33 does not act as a restriction which would produce adrop in pressure t-hereacross but is merely a replaceable orifice usedto limit the maximum gas flow into the well tubing string through thegas lift valve.

When the column of fluid in the tubing string has been suflicientlylightened or aerated, the pressure of the fluids in the tubing acting onthe valve head 50 decreases and the valve head is moved toward the seatto close off flow, and when the pressure decreases to substantially thesame predetermined value as that impressed upon the valve by means ofthe spring and the fluid confined in the chamber 89, the valve plungeror stem is moved downwardly and the valve head is moved into engagementwith the seat 48 to close off flow of fluids through the seat from theorifice inlet 33. When the valve is in its closed position, the fluidpressure across the orifice 33 equalizes, but this pressure, while beinggreater than the pressure within the bore of the lower sub, does nottend to move the valve to the open position, since the area of the valveseat engaged by the valve tip 51 is substantially equal to the areasealed off by the seal means 60 in the body engaging the plunger or stem57. The valve thus opens and closes at substantially the same pressure,and this pressure may be adjusted to any desired value by varying thecompression of the spring 83 by rotation of the adjusting screw 84 andby varying the pressure of the gas confined in the chamber 89.

In use, the gas lift valve 10 is disposed in the pocket 20 with theports in the cap at the lower end of the valve in communication with thebore of the housing and the tubing thereabove and therebelow through theopening 22 at the lower end of the pocket. The lower end of the welltubing is open and ermits flow of well fluids produced by the wellupwardly through the tubing, and the pressure of the fluids in thetubing act through the passage 22 and the openings 36 in the cap pastthe check valve 45 which is in its normal non-sealing position, and thuspass upwardly through the bore of the lower sub and the bore 52 of thevalve 53 of the plunger and the lateral port 54 into the chamber 61where the pressure acts on the bellows 65.

The orifice member 33 provides communication between the tubing-casingannulus exteriorly of the landing nipple 11 and the interior of thepocket 13, and as well fluids are produced by the well and flow upwardlyin the well tubing and within the landing nipple, the pressure exertedon the bellows 65 increases to move the plunger 57 upwardly and lift thevalve head t) and the tip 51 thereof upwardly off the seat 48 permittingfluids to flow inwardly through the orifice 33 into the bore of the body30 and downwardly therefrom through the bore of the sub 34 past thecheck valve 45 and outwardly through the openings 36 and the cap 35 tothe bore of the landing nipple through the passage 22 to aerate and liftthe fluids present in the tubing. The column of fluids in the tubingabove the orificed inlet member 33 of the gas lift valve increases untilthe same attains a predetermined height and produces a hydrostaticpressure which exerts a force of predetermined value in the mannerdescribed acting on the bellows 65 against the force of the spring 83and the charge of gas, if any, in the chamber 89. When the valve head 50moves upwardly to the open position, the gas from the annulus exteriorlyof the landing nipple passing inwardly through the inlets 21 and theorifice 33 flows downwardly past the valve head 50 and into the bore ofthe tubing to lift the column of fluid therein. When the valve head 50is moved to its open position, substantially the full pressure of gasentering through the openings 21 will pass into the gas lift valve andact on the bellows, tending to move the same upwardly to ward its fullyopen position, whereupon the seal member 64 engages the seal surface 63to prevent further application of pressure to the bellows and theengagement of the shoulder 55 with the shoulder 58 limits upwardmovement of 'the plunger to prevent mechanical compressive damage to thebellows.

Due to the inertia of the column or slug of liquid in the tubing abovethe port 22 of the pocket, the flow of gas through the gas lift valve isslow at first but increases as the upward movement of the liquid columnthrough the tubing is accelerated. As the gas from the exterior of thelanding nipple enters the tubing at an increasing rate to aerate andaccelerate flow, the column of liquid is lightened in weight and thehead pressure of the column acting on the valve is reduced, whereby adrop in pressure is created across the annular orifice between the tip51 of the valve and 'the seat 48. As a result, the valve head 5% ismoved downwardly by the force of the spring 83 and the pressure of thecharge of gas, if any, in the chamber 89 acting downwardly on thebellows 65, whereupon the tip 51 is moved downwardly in the bore of theseat 48 to reduce the size of the annular orifice therebetween torestrict the flow of gaseous fluid therethrough and thereby reduce therate of entry of gas into the column of liquid in the tubing. Theadmission of gas through the valve 10 is thus metered by the valve head50 as it moves toward and away from the seat 48 and a continuous flow ofgaseous lifting fluid is admitted through the seat into the bore of thelanding nipple to lift the well liquids present therein, resulting in acontrolled continuous metered lifting of the fluids by means of thevalve.

As the well fluids are lifted through the tubing, the weight of thecolumn of liquid therein will be reduced until ultimately the valve head50 will be moved downwardly until the tip 51 thereon engages the seat 48to shut off flow of fluids through the annular orifice therebetween,whereupon further admission of gas through the inlet orifice 33 isprohibited until the column of liquid present in the bore of the tubingrises to such an extent that the valve tip will be lifted off the seat48 in the manner previously described. It will thus be seen that thevalve is dependent upon fluid conditions present in the bore of thetubing for control of the operation of such valve.

It will also be seen that the valve may be used in offset pockets tocontrol admission of lifting gas to an inner tubing, or may be mountedin the usual manner on the exterior of the tubing; and that the valvefunctions to provide for a continuous metered flow of lifting fluidthrough the valve into the bore of the tubing to lift the column offluid therein.

It will also be seen that the operation of the valve is independent ofpressure conditions exteriorly of the well tubing, and that the valveopens only when the fluid pressure in the tubing attains a predeterminedvalue at the discharge opening 22 of the pocket and the opening 36 ofthe valve assembly; and that, as a result, the valve is particularlyadapted for use in multiple string, multiple zone well installations.

It will further be seen that due to the counter-balancing of the forcesexerted by the fluid pressure entering the housing through the orificemember 33 and acting on the valve head 50 and the reduced lower portion59 of the stem 57, the valve is opened and closed at substantially thesame value of pressure occurring in the flow passage of the bore of thesub 34 therebelow.

It will also be seen that the valve may be used in wells producing bothgases and fluids or liquids to cause the produced gases present in thewell casing to transport the liquids produced by the well from thebottom of the well to the surface through the inner well tubing.

The foregoing description of the invention is explanatory only, andchanges in the details of the construction illustrated may be made bythose skilled in the art, within the scope of the appended claims,without departing from the spirit of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. A well tool including: a housing having a flow passage and a lateralaperture intermediate the ends of said housing communicating said flowpassage with the exterior of the housing; a valve means comprising anelongate body longitudinally slidable in said housing, said housinghaving a valve seat engageable by said elongate body when said elongatebody is moved in one direction to one'extreme longitudinal position insaid housing; sealing means between said elongate body and said housing,said ,lateral aperture being disposed between said valve seat and saidsealing means, said elongate body closing said flow passage 'to preventflow of fluids from said aperture to said flow passage when saidelongate body is in said one extreme longitudinal position; and meansresponsive to fluid pressure comprising a bellows having one endconnected to said elongate body and another end connected to saidhousing to form a chamber in said housing between said housing and saidbellows; said elongate body having a longitudinally extending internalflow passage formed therein communicating at one end with the flowpassage of the housing and extending longitudi nally of said elongatebody past said sealing means to the exterior of said elongate body at apoint communicating With said chamber in the housing to conduct fluidpressure from the flow passage of said housing to said means responsiveto fluid pressure for actuating said elongate body; said elongate bodyand said housing having coengagea'ble means for closing said chamberfrom said passageway of said elongate body when said elongate body movesto open position, said elongate body and said valve seat providing anannular flow passage therebetween smaller in area than the area of thelateral aperture of the housing controlling flow from said lateralaperture through said seat to the flow passage of the housing, wherebythe elongate body of the valve means is movable in response to fluidpressure of the fluid in the flow passage of the housing.

2. A well tool including: a housing having afloW passage and a lateralaperture intermediate the ends of said housing communicating said flowpassage with the exterior of said housing; valve means comprising anelongate body longitudinally slidable in said housing; a valve seat inthe passage of said housing engageable by said elongate body when saidelongate body is moved in one direction in said housing to one extremeclosed position therein; sealing means between said elongate body andsaid housing, said lateral aperture being disposed between said valveseat and said sealing means, said elongate body closing said flowpassage of said housing to prevent flow-of fluids from said aperture:through said flow passage and seat when said elongate body is in saidone extreme longitudinal position relative to said housing; saidelongate body having a flow passage therein communicating at one endwith said flow passage of said housing adjacent said valve seat andextending past said sealing means to the passage of said housingtherebeyond; fluid pressure responsive means operative'ly associatedwith said elongate body and said housing and exposed to the pressurefrom said flow passage of said elongate body for moving said elongatebody from said one extreme position to an open opposite extreme positionpermitting flow of fluids between said aperture and said flow passagethrough said seat; the flow passage through said seat between said seatand said valve means being smaller in area than the area of the lateralaperture of the housing, whereby fluid pressure flowing through saidlateral aperture has substantially no eflecton operation of the valveand the elongate body is movable between open and closed positions inresponse to fluid pressure of fluid in the flow passage of the valveseat; shutoif means .on said elongate body and said housing spacedlongitudinally from each other when said elongate body is in said oneextreme position to expose said fluid responsive means ,to the fluidpressure from the passage of said elongate body, and movable intoengagement with each other when said elongate body is in said oppositeextreme longitudinal position in said housing to shut oil? flow of fluidfrom said passage to said fluid responsive means to protect-the sameagainst such pressure.

3. A well tool including: a housing having a flow passage and a lateralaperture intermediate the ends of said housing communicating said flowpassage with the exter-ior of said housing; valve means longitudinallyslidable in said housing; a valve seat in said housing passage and 1:0engageable by said valve means when said valve means is moved in onedirection in said housing to one extreme longitudinal closed positiontherein and with said valve means providing an annular flow passagetherebetween (having a smaller area than the area of the lateralaperture one extreme longitudinal position and movable to an op positeextreme longitudinal position to open said passage and seat to flow fromsaid aperture through said passage and seat; said valve means having anelongate flow-passage extending axially therethrough and communicatingat one end With the chamber between the housing and the bellows and atits opposite end with said flow passage to said housing adjacent saidseat whereby fluid pressure from said flow passage of said housing is incommunication with said chamber and may pass through said valve meanspassage and to said chamber to act on said bellows to move said valvemeans to open position; the smaller annular passage through said valveseat between said valve seat and said valve means controlling flow offluid through said housing passage from said lateral aperture of thehousing, whereby fluid flowing through said lateral aperture hassubstantially no effect on operation of the valve and said valve meansis actuated by the pressure of the fluids in the flow passage of thehousing downstream of said valve seat; and seal means onsaid housing andsaid valve means spaced from each other when said valve means is in saidone extreme longitudinal position and engageable when said valve meansis in said opposite extreme longitudinal position to seal off thechamber between said rbellows and said housing from the fluid pressureentering said chamber from the outlet of the passage in the valve meansto protect said bellows against action of said pressure,

4. A well tool including: a housing having a flow passage and a lateralaperture intermediate the ends of said housing communicating said flowpassage with the exterior of said housing; valve means comprising anelongate body longitudinally slida-ble in said housing, said housinghaving a valve seat engaged by said elongate body when said elongatedbody is moved in one direction to one extreme longitudinal position insaid housing to close off flow through said passage and seat and whenmoved in an opposite direction to an opposite extreme longitudinal openposition in said housing providing with said valve seat and saidelongatebody an annular restricted flow passage therethrough having a smallercross-sectional area than the area of a lateral aperture of the housing;fluid pressure responsive means operatively associated with said housingand said elongate body for moving said elongate body from said oneextreme closed position to an opposite extreme open position permittingfluid to flow through said aperture and said flow passage and said seat,said fluid pressure responsive means comprising an elongate cylindricalbellows having one end connected to said elongate member and another endconnected to said housing to form a chamber between said housing and theexterior of said bellows; sealing means slidably sealing between saidelongate body and said housing, said lateral aperture of said housingbeing disposed between said valve seat and said sealing means, saidelongate body closing said seat to prevent flow of fluids from saidaperture through said flow passage and seat when said elongate body isin said one extreme longitudinal position; said elongate valve meanshaving an elongate flow passage formed therein communicating at one endwith the flow passage of the housing adjacent the valve seat andextending at its opposite end past said sealing means and communicatingwith the chamber between said housing and the exterior of said bellowspast such sealing means to expose said bellows to fluid pressure fromsaid flow passage of said housing adjacent the seat for acting on saidbellows to move said elongate valve body to said opposite extremeposition; means biasing said elongate valve means toward said valveseat; the smaller annular passage through said valve seat between saidvalve seat and said valve means controlling flow of fluid through saidhousing passage from said lateral aperture of the housing, whereby fluidflowing through said lateral aperture has substantially no effect onoperation of the valve and said valve means is actuated by the pressureof the fluids in the flow passage of the housing downstream of saidvalve seat; and shut-off means on said elongate valve body and saidhousing spaced from each other when said valve body is in said oneextreme longitudinal position engaging said seat and engageable witheach other when said elongate valve body is in said opposite extremelongitudinal position, said shut-off means being disposed between thepassage of the valve member and the bellows to prevent fluid pressurefrom said passage acting on said bellows when said shut-off means are inengagement.

5. In a well tool of the character set forth in claim 4, biasing meansin said body engaging said elongate valve body and biasing said elongatevalve body toward said valve seat.

6. In a well tool of the character set forth in claim 4, adjustable stopmeans in said housing; and means biasing said elongate valve body towardsaid valve seat and comprising a helical coil spring confined in saidhousing and engaging said elongate body at one end at is opposite endengaging said adjustable stop means in said housing whereby the forceapplied by said spring to said valve body may be adjusted by adjustmentof said stop means in said housing.

7. A well tool of the character set forth in claim 4 wherein the housingpassage beyond said bellows on the side of said bellows opposite saidseat is closed by a closure member to form a chamber in said housingbetween said housing and said bellows for receiving fluid under pressuretherein, whereby fluid under pressure may be introduced into saidchamber to act on said bellows to bias said elongate valve body towardsaid seat to close said seat.

8. A valve of the character set forth in claim 4 wherein the housingpassage beyond said bellows on the side of said bellows opposite saidseat is closed by a closure member to form a chamber in said housingbetween said housing and said bellows for receiving fluid pressuretherein whereby fluid under pressure may be introduced into said chamberto act on said bellows to bias said elongate valve body toward said seatto close off flow through said seat; and resilient means is disposed insaid housing operatively associated with said elongate valve bodybiasing said elongate valve body toward said valve seat and comprising ahelical coil spring confined in said housing and engaging said elongatemember at one end and at its opposite end engaging said closure memberin said housing passage whereby the force applied by said spring to saidvalve body may be adjusted by adjustment of the position of said closuremember in said housing.

9. A well tool including: an elongate valve housing having a flowpassage therein open at one end exteriorly of the housing and closed atthe opposite end of said housing; a lateral inlet opening intermediatethe ends of said housing and communicating the exterior of said housingwith the flow passage therein; a valve seat within the flow passage ofsaid housing between said lateral aperture and the open outlet end ofthe flow passage; an elongate valve member movable longitudinally in thepassage of the body between a first extreme longitudinal closed positionin engagement with said seat and a second extreme longitudinal openposition out of engagement with said seat, said valve member and saidseat providing an annular restricted orifice therebetween having asmaller cross-sectional area than the area of the lateral aperture ofthe housing; seal means between said valve member and said housing inthe flow passage and disposed in the housing on the side of saidaperture opposite said seat whereby fluid pressure entering through thelateral aperture into said passage is directed toward said seat and isprevented from flowing in said passage between said valve member andsaid body other than to said seat; an elongate cylindrical fluidpressure responsive bellows surrounding said valve member and connectedat one end to said housing and at the opposite end to said valve memberand forming a chamber in said housing between said housing and saidbellows on the opposite side of said seal means from said valve seat;said valve member having a longitudinal flow passage therein open at oneend of said valve member and communicating with the flow passage of saidbody adjacent said seat and at its opposite end communicating laterallyexteriorly of said valve member with said closed chamber between saidseal means and said bellows whereby fluid pressure entering said passagefrom adjacent said seat is conducted to the chamber between said bellowsand said housing above said seal means and said valve member is moved inresponse to pressure in said housing passage adjacent said seat; biasingmeans between the closed end of said body and said valve member biasingsaid valve member to closed position engaging said seat, fluid pressurefrom the passage of the body passing through the passageway of the valvemember to the chamber between the housing and the bellows acting on saidbellows to move said valve member to open position; the smaller annularpassage through said valve seat between said valve seat and said meanscontrolling flow of fluid through said housing passage from said lateralaperture of the housing, whereby fluid flowing through said lateralaperture has substantially no effect on operation of the valve and saidvalve means is actuated by the pressure of the fluids in the flowpassage of the housing downstream of said valve seat; shut-off means onsaid housing and on said valve member coengageable When said valve meansis moved to open position to shut off fluid pressure from said passageof said valve member to said chamber between said bellows and saidhousing to protect the bellows from such pressure; said shut-off meansbeing moved to open position when said valve member is moved to saidfirst extreme longitudinal closed position in engagement with said valveseat, whereby said bellows is acted upon by the fluid pressure from thepassage of the valve housing to move said valve member to open positionand to permit fluid pressure from said lateral inlet of said housing toenter said valve passage to coact with the pressure from beyond the seatto move said valve member to said second extreme position, said shutoffmeans protecting said bellows from such action of the fluid pressurewhen the valve is in such second extreme open position.

10. A well tool of the character set forth in claim 4, wherein theshut-off means includes: adjacent annular sealing and stop surfaces insaid housing; an enlarged annular flange member on said valve memberhaving an abutment shoulder engaging the stop surface in said housingwhen said valve member is moved to said other extreme longitudinalposition to limit movement of said valve member in said housing; andannular sealing means on said flange engageable with the sealing surfaceof said housing for sealing therebetween to prevent fluid pressurepassing said flange and said sealing and stop surfaces.

11. A device of the character set forth in claim 4, wherein said valvemeans includes: a valve head having an elongate tip extending throughsaid annular seat and movable longitudinally toward and away fromengagement with said seat to provide a variable annular orifice betweensaid tip and said seat for metering flow of fluids 13 therethrough inresponse to the pressure of the fluids within the tubing string.

12. A device of the character set forth in claim 2 wherein said valveseat is: an annular seat and said valve means includes a valve headhaving an elongate tapered tip extending through said annular seat andmovable longitudinally toward and away from engagement with said seat toprovide an annular orifice between said tip and said seat for meteringflow of fluids therethrough in response to the pressure of the fluidsdownstream of said seat, said valve head being carried by said elongatebody and of suflicient length to remain disposed in said annular seatwhen said shut-01f means is engaged position.

13. A well too] including: a housing having a flow passage and a lateralaperture intermediate the ends of said housing and communicating saidflow passage with the exterior of said housing; valve meanslongitudinally slidable in said housing; a valve seat in said housingengageable by said valve means when said valve means is moved in onedirection in said housing to one extreme closed position; sealing meansbetween said valve means and said housing spaced beyond the lateralaperture from said valve seat whereby said lateral aperture is disposedbetween said valve se-at and said sealing means; said valve meansclosing said flow passage to prevent flow of fluids from said aperturethrough said seat when said valve means is in said one extremelongitudinal closed position; means operatively associated with saidvalve means and said housing and exposed to fluid pressure conductedfrom downstream of said seat in said flow passage of said housing formoving said valve means in a direction opposite to said one directionfrom said one extreme longitudinal closed position when said fluidpressure in said passage increases to a predetermined value; said valvemeans including an annular seat and a valve head having an elongate tipextending through said annular seat and movable longitudinally towardengagement with and away from engagement withsaid seat to provide avariable annular orifice between said tip and said seat having across-sectional area smaller than the lateral aperture of said housingfor metering flow of fluids through said housing from said lateralaperture to the flow passage beyond said valve seat; and sealing meanson said valve means and said housing spaced from each other out ofsealing engagement when said valve means is in said one extremelongitudinal closed position and engagebale when said valve means is issaid other extreme longitudinal open position to seal ofl the pressurein said flow passage from said means responsive to fluid pressure formoving said valve means in said housing.

14. A well tool including: a housing having a flow passage with adischarge opening adjacent one end of said housing, sad housing having alateral inlet aperture intermediate its ends communicating the exteriorof said housing with the flow passage thereof at a point spaced fromsaid discharge opening; an annular valve seat in said flow passage ofsaid housing between said lateral aperture and said discharge opening;elongate valve means longitudinally slidable in said housing and havinga per tion disposed within said valve seat and movable longitudinally inone direction relative thereto into a closed position in engagement withsaid seat and in the opposite direction to an open position out ofengagement with said valve seat and providing an annular flow orificetherebetween smaller in area than said lateral aperture of said housing;sealing means in said housing between said valve means and said housingspaced beyond the lateral aperture from said valve seat, whereby saidlateral aperture is disposed between said valve seat and said sealingmeans; a longitudinal internal flow conduit extending from a pointadjacent the valve seat to a point in said housing spaced longitudinallybeyond the sealing means in said housing;

pressure responsive means operatively associated with said elongatevalve means and said housing for moving said valve means from c-losed toopen positions in response to fluid pressure in said flow passagebetween said valve seat and said discharge opening in excess of apredetermined value; said internal flow conduit providing a flow passagefor fluid from the flow passage of the valve housing between the valveseat and the discharge opening of said housing to the pressureresponsive means for conducting fluid pressure from said flow passage ofsaid housing to said pressure responsive means for moving said valvebetween closed and open positions in response to such fluid pressure;the annular flow orifice between said valve means and said valve seatbeing variable in size as the valve means is moved with respect to saidseat for controlling flow from said lateral inlet aperture through saidseat to the discharge opening of the housing, whereby fluid pressureentering the flow passage of the housing through the lateral aperturehas substantially no effect on operation of the valve and the elongatevalve member is movable in response to fluid pressure of the fluid inthe flow passage of the housing downstream of said annular orifice.

15. A well tool of the character set forth in claim 14, whereincoengageable means are provided on the housing and the elongate valvemeans between said pressure responsive means and said flow passage fromsaid valve seat to said pressure responsive means engageable when saidvalve means is in said open position to close off access of fluidpressure from said internal flow passage to said pressure responsivemeans.

16. A well tool of the character set forth in claim 14 wherein thelongitudinal internal conduit extending from a point adjacent the valveseat to a point in said housing spaced longitudinally beyond the sealingmeans in said housing comprises a longitudinal conduit formed in saidelongate movable valve means and extending from the end thereof adjacentthe seat longitudinally of said valve means to a point spaced from saidend beyond the sealing means in the housing between the valve means andthe housing and opening from said elongate valve means to said pressureresponsive means, whereby fluid pressure from the flow passagedownstream of the end of said valve means adjacent the valve seat isconducted through said longitudinal conduit in said valve means to saidpressure responsive means for acting on said pressure responsive meansto move said valve means between closed and open positions.

17. A well tool of the character set forth in claim 16 wherein theportion of the elongate valve means longitudinally movable within thevalve seat comprises an elongate tip tapering toward the end of saidvalve means and extending through the seat and having its larger portionmovable longitudinally toward and away from engagement with said seat toprovide said variable annular orifice between said tip and said seat formetering flow of fluids therethrough in response to the pressure of thefluids within the flow passage of the housing between the valve seat andthe discharge opening thereof.

References Cited UNITED STATES PATENTS 2,250,464 7/1941 Boynton l37-1552,688,553 2/1954 Howard 137-155 2,797,700 7/1957 McGowen 1371552,815,764 12/1957 Bryan 137-155 2,904,305 9/ 1959 Novot'ny 251-322 X2,982,226 5/1961 Peters l03-232 X 3,066,690 12/1962 Tausch 137-155 ALANCOHAN, Primary Examiner.

1. A WELL TOOL INCLUDING: A HOUSING HAVING A FLOW PASSAGE AND A LATERALAPERTURE INTERMEDIATE THE ENDS OF SAID HOUSING COMMUNICATING SAID FLOWPASSAGE WITH THE EXTERIOR OF THE HOUSING; A VALVE MEANS COMPRISING ANELONGATE BODY LONGITUDINALLY SLIDABLE IN SAID HOUSING, SAID HOUSINGHAVING A VALVE SEAT ENGAGEABLE BY SAID ELONGATE BODY WHEN SAID ELONGATEBODY IS MOVED IN ONE DIRECTION TO ONE EXTREME LONGITUDINAL POSITION INSAID HOUSING; SEALING MEANS BETWEEN SAID ELONGATE BODY AND SAID HOUSING,SAID LATERAL APERTURE BEING DISPOSED BETWEEN SAID VALVE SEAT AND SAIDSEALING MEANS, SAID ELONGATE BODY CLOSING SAID FLOW PASSAGE TO PREVENTFLOW OF FLUIDS FROM SAID APERTURE TO SAID FLOW PASSAGE WHEN SAIDELONGATE BODY IS IN SAID ONE EXTREME LONGITUDINAL POSITION; AND MEANSRESPONSIVE TO FLUID PRESSURE COMPRISING A BELLOWS HAVING ONE ENDCONNECTED TO SAID ELONGATE BODY AND ANOTHER END CONNECTED TO SAIDHOUSING TO FORM A CHAMBER IN SAID HOUSING BETWEEN SAID HOUSING AND SAIDBELLOWS; SAID ELONGATE BODY HAVING A LONGITUDINALLY EXTENDING INTERNALFLOW PASSAGE FORMED THEREIN COMMUNICATING AT ONE END WITH THE FLOWPASSAGE OF THE HOUSING AND EXTENDING LONGITUDINALLY OF SAID ELONGATEBODY PAST SAID SEALING MEANS TO THE EXTERIOR OF SAID ELONGATE BODY AT APOINT COMMUNICATING WITH SAID CHAMBER IN THE HOUSING TO CONDUCT FLUIDPRESSURE FROM THE FLOW PASSAGE OF SAID HOUSING TO SAID MEANS RESPONSIVETO FLUID PRESSURE FOR ACTUATING SAID ELONGATE BODY; SAID ELONGATE BODYAND SAID HOUSING HAVING COENGAGEABLE MEANS FOR CLOSING SAID CHAMBER FROMSAID PASSAGEWAY OF SAID ELONGATE BODY WHEN SAID ELONGATE BODY MOVES TOOPEN POSITION, SAID ELONGATE BODY AND SAID VALVE SEAT PROVIDING ANANNULAR FLOW PASSAGE THEREBETWEEN SMALLER IN AREA THAN THE AREA OF THELATERAL APERTURE OF THE HOUSING CONTROLLING FLOW FROM SAID LATERALAPERTURE THROUGH SAID SEAT TO THE FLOW PASSAGE OF THE HOUSING, WHEREBYTHE ELONGATE BODY OF THE VALVE MEANS IS MOVABLE IN RESPONSE TO FLUIDPRESSURE OF THE FLUID IN THE FLOW PASSAGE OF THE HOUSING.